Oral and pharyngeal cancer has remained a persistent oral health problem among the elderly in the United States. Survival rates have shown little improvement over the past decades. Health disparities also exist such as higher incidence and lower survival among racial and ethnic minority populations. Baseline and trend data by which progress can be measured are lacking-particularly among the underserved populations most in need of intervention. The goals of this research are to derive and validate an algorithm based on Medicare claims to identify incident oral and pharyngeal cancer cases among Medicare beneficiaries. This algorithm will be derived using the Surveillence, Epidimiology and End Result (SEER)-Medicare linked database. These data provide a unique linkage of the SEER tumor registry with Medicare claims, ie, it combines the "gold standard" tumor registry with the health claims of the largest insurer of the elderly in the United States. Half of the data will be randomly allocated to determine the algorithm, and the other have will be used for validation. This algorithm will have broad applications that include generating and improving upon oral and pharyngeal cancer baseline and trend data, which the National Institutes of Dental and Craniofacial Research have noted are lacking. This algorithm will also allow future studies to link cancer diagnoses with Medicare claims to study of prevention, early detection and treatment of oral and pharyngeal cancer. The strength in numbers of this population-based study, including racial and ethnic minority popuations, make this research a useful first step toward improving the oral health of the elderly as well as reducing health disparities. For this study, we will use Medicare claims to determine the best combination of procedures and diagnoses that identify individuals with oral and pharyngeal cancer. The ability to identify these cancer cases from Medicare claims will facilitate a cost-effective way to accurately measure the burden of oral and pharyngeal cancer, and to investigate the effectiveness of prevention, early detection and treatment strategies for this debilitating disease. [unreadable] [unreadable] [unreadable]